1. Field of the Invention
The present invention relates to a data line driver of a plane type display apparatus such as a liquid crystal display (LCD) apparatus.
2. Description of the Related Art
In a plane type display apparatus including a panel having data lines (or signal lines), scan lines (or gate lines) and cells each located at one intersection between the data lines and the scan lines, a data line driver for driving the data lines, and a scan line driver for driving the scan lines.
In order to improve the quality of a moving image, i.e., in order to improve the removing effect of a residual image of a moving image, the data line driver switches a gradation voltage with a black voltage (see: JP-2001-60078-A). For example, the data line driver includes a switch circuit for applying the black voltage instead of the output signals of an output buffer to data lines (see: FIG. 2 of JP-2001-60078-A) or a switch circuit for generating black data instead of the output signal of a data register (see: FIG. 3 of JP-2001-60078-A). This will be explained later in detail.
In the above-described prior art data line driver, however, since the switch circuit requires an enormous number of switches, the size of the data line driver is increased. Also, if another fixed intermediate gradation voltage, not the black voltage, is required to be applied to the data lines, the connections therefor are so complicated that the size of the data line driver is further increased.